If the team is 2-8 how does the team benefit by Tony quitting? A distraction when you are already eleminated doesn't do much harm.
Plus he will have about six million reason to wait to be fired instead of quitting.
If there was one thing that I admired about Dave Wanstadt was that once he knew he was going to be fired at the end of the season, he gave his resignation and the search for a new head coach commenced. Even Huizenga mentioned that it helped him being able to start the search for a new head coach before the season was over. It did help the team too because all the talk the last couple weeks of the season would have revolved around him. Once he quit, there wasn't must left to say and the players could focus on the last couple weeks of the season. It may not do much harm, but it doesn't help either.
Now I don't know what the contract situation was for Wanny when he resigned, he may have been in the last year of his contract and I won't hold it against Tony if he decides to wait for them to fire him, but I would hope that he would go in to Ross and say, "If you're gonna fire me at the end of the year anyway, just do it now and get it over with".